1983与1985年夏季北半球500hPa高度场大气低频波的振荡特征   总被引：4，自引：1，他引：4  

孙安健  唐国利  黄荣辉 《大气科学》1994,18(5):576-585

本文利用观测资料分析了1983与1985年夏季半球500hPa高度场大气低频波的振荡特征。结果表明，1983年（厄尔尼诺年）夏季热带中、东太平洋和印度洋以及东亚季风区上空的低频振荡比1985年（反厄尔尼诺年）夏季的低频振荡强，而热带西太平洋的情况恰好相反。这是由于反厄尔尼诺年夏季热带西太平洋对流活动强盛所致。分析结果还表明：1983年夏季低频波基本上是东传的；1985年夏季，在中高纬度地区低频波主要还是东传，热带是西传。西藏高原是大气低频振荡的汇区。  相似文献   

激光束光学系统的变焦理论     

何平安  林银森 《武汉大学学报(信息科学版)》1994,(1)

从高斯光束经过光学系统的传输与变换规律出发，借助于高斯括号的性质，研究了激光束光学系统的变焦特性，导出了机械补偿式激光束变焦系统的变焦方程及补偿点位置方程，并给出了计算实例。  相似文献   

The impact of high altitude aircraft on the ozone layer in the stratosphere     

Xue Xi Tie  Guy Brasseur  Xing Lin  Pierre Friedlingstein  Claire Granier  Philip Rasch 《Journal of Atmospheric Chemistry》1994,18(2):103-128

The paper discusses the potential effects on the ozone layer of gases released by the engines of proposed high altitude supersonic aircraft. The major problem arises from the emissions of nitrogen oxides which have the potential to destroy significant quantities of ozone in the stratosphere. The magnitude of the perturbation is highly dependent on the cruise altitude of the aircraft. Furthermore, the depletion of ozone is substantially reduced when heterogeneous conversion of nitrogen oxides into nitric acid on sulfate aerosol particles is taken into account in the calculation. The sensitivity of the aerosol load on stratospheric ozone is investigated. First, the model indicates that the aerosol load induced by the SO₂ released by aircraft is increased by about 10–20% above the background aerosols at mid-high latitude of the Northern Hemisphere at 15 km for the NASA emission scenario A (the NASA emission scenarios are explained in Tables I to III). This increase in aerosol has small effects on stratospheric ozone. Second, when the aerosol load is increased following a volcanic eruption similar to the eruption of El Chichon (Mexico, April 1982), the ozone column in spring increases by as much as 9% in response to the injection of NO _x from the aircraft with the NASA emission scenario A. Finally, the modeled suggests that significant ozone depletion could result from the formation of additional polar stratospheric clouds produced by the injection of H₂O and HNO₃ by the aircraft engines.  相似文献   

高原东部地区一次雹云成雹过程的数值模拟   总被引：1，自引：2，他引：1  

马林  赵仕雄  张国庆 《高原气象》1994,(2)

本文利用一维半时变双参数积云模式，对高原东部地区一次西风槽影响下的冰雹天气过程进行了数值模拟。讨论了该雹云内的动力、热力特点以及过冷云滴、冰晶、霰、雹的产生和转化以及降水粒子碰并增长等物理过程。对高原雹云的成雹机制作了初步探讨  相似文献   

TROPICAL ATMOSPHERIC NONLINEAR STEADY RESPONSE SOLUTION UNDER EFFECTS OF PAIRED HEAT SOURCES OF CONTRASTING NATURE          下载免费PDF全文

周学龙  孙照渤 《Acta Meteorologica Sinica》1994,(3)

Based on steady semi-geostrophic model equations,analysis is carried out of the linear and nonlinearmodification/response of the tropical atmosphere to the forcing of ideal paired heat sources of contrasting nature.Re-suits show that the linear part is dominant in the steady response but the nonlinear modification is quite noticable in theneighborhood of the heat source and between the paired sources,and the barotropic mode and second baroclinic modeplay a different role in the modification,with the barotropic(second baroclinic)mode modification depending largely onthe Rossby wave self-interaction(the magnitude due to the Kelvin-Rossby wave interaction)between the pairedsources.  相似文献   

亚欧500hPa旬平均形势预报的改进及检验     

任金声  李晓东  林玉成  吴金瑞 《气象》1994,20(9):34-37

利用数值预报产品，对原亚欧５００ｈＰａ旬平均形势预报方程作了改进。除对空间和时间尺度上作了改进外，在预报因子的选择上，由亚欧地区的单点相关，扩张至整个北半球的相关；并根据长波天气系统的气候地理分布和遥相关分析等方法，选择关键区作为候选因子，组建了新的形势预报方程。经检验比较，新的形势预报方程高度距平正确和长波系统位置正确率分别提高了０．１５－０．２０和０．１０。  相似文献   

Geochemistry　of　Thermal－Mineral　Waters　in　Siping＇an　District，　Shanxi　Province，　China     

Wan Yanxin  Sun Lianfa 《中国地质大学学报(英文版)》1994,(1)

ＧｅｏｃｈｅｍｉｓｔｒｙｏｆＴｈｅｒｍａｌ－ＭｉｎｅｒａｌＷａｔｅｒｓｉｎＳｉｐｉｎｇ＇ａｎＤｉｓｔｒｉｃｔ，ＳｈａｎｘｉＰｒｏｖｉｎｃｅ，Ｃｈｉｎａ￥ＷａｎＹａｎｘｉｎ；ＳｕｎＬｉａｎｆａ（ＤｅｐａｒｔｍｅｎｔｏｆＨｙｄｒｏｇｅｏｌｏｇｙａｎｄＥｎ...  相似文献   

Discovery of Early Tertiary Hydrothermal Activity and Its Significance in Oil／Gas Geology,Dougpu Depression,Henan Province,China     

朱家祥  朱家蔚等 《中国地球化学学报》1994,13(3):270-283

Data from the super-deep wells(PS10,PS14 and YS1)led to the discovery of widespread met-al-bearing hydrothermal fluids (or hot brines) related to basic magmas in the Lower Tertiary clastic sequence in the Dongpu Depression .In terms of SEM and EDAX analyses, pore-casting thin section examination of sandstone ,the composition and forming temperature of fluid inclusions ,the trace ele-ment composition of mustone and kerogen and organic geochemical analyses, it is demonstrated that the hydrothermal fluids existing in the area studied are ejecting fluids, which have a close bearing on diagenesis and sedimentation, rather than intrusive veins along the tectonic fractures.The main indicators of hydrothermal activity are:(1)abnormal alteration of kerogen;(2) high-temperature altered mineral assemblage;(30abnormal distribution of hydrocarbons;(4) specific assemblages and abnormal contents of heavy metals in mudstone and kerogen;(5) specific composi-tion of complex compounds and assemblages of fluid inclusions in sandstone;(6) periodic basaltic magma activity.Results of geological observations and laboratory simulating experiments demonstrated that the hydrothermal fluids have a close bearing on hydrocarbon generation in the Dongpu Depression. Two aspects of the effect of hydrothermal fluids are noticed:hydrothermal hydrocarbon production and strong metal catalysis in oil and gas generation.  相似文献   

青藏高原地区地表及行星反射率   总被引：5，自引：3，他引：5       下载免费PDF全文

孙治安  翁笃鸣 《应用气象学报》1994,5(4):394-401

文章讨论了利用ISCCP卫星观测资料确定青藏高原地区地表反射率的方法，在无积雪地区和季节，地表反射率可以ISCCP可见光反射率为基础，在模式计算过程中，假定紫外反射率以及红外与可见光反射率的比值分别为常数。敏感性试验表明，由这两个假设所产生的误差并不显著。在有积雪地区或季节，地表平均反射率可直接由ISCCP可见光反射率表示。试验结果与地面实际观测作了比较，除沙漠区外，两者比较一致。文中还计算了高原晴天行星反射率。经与ERBE卫星观测比较，发现从5月至9月高原周围沙漠区气溶胶对辐射平衡有较显著的影响。而在其  相似文献   

TROPICAL ATMOSPHERIC NONLINEAR STEADY RESPONSE SOLUTION UNDER EFFECTS OF PAIRED HEAT SOURCES OF CONTRASTING NATURE^*          下载免费PDF全文

Zhou Xuelong  Sun Zhaobo 《Acta Meteorologica Sinica》1994,8(3):356-364

Based on steady semi-geostrophic model equations,analysis is carried out of the linear and nonlinear modification/response of the tropical atmosphere to the forcing of ideal paired heat sources of contrasting nature.Resuits show that the linear part is dominant in the steady response but the nonlinear modification is quite noticable in the neighborhood of the heat source and between the paired sources,and the barotropic mode and second baroclinic mode play a different role in the modification,with the barotropic(second baroclinic)mode modification depending largely on the Rossby wave self-interaction(the magnitude due to the Kelvin-Rossby wave interaction)between the paired sources.  相似文献